With the advancement in scientific technologies and the modularization and miniaturization of camera lens, it is now possible to produce digital cameras having a very small size, and most of currently available mobile phones are provided with the function of a digital camera. On the other hand, to highlight the differences between the advanced camera devices and the low-level camera devices, higher image quality and more functions, such as highly increased pixels, multi-point auto-focus (AF) function, anti-shake (AS) function, etc., have been further added to the advanced camera devices.
However, every new function added to the image capturing module of a camera device would necessitate the increase of a corresponding modular mechanism to thereby increase the size of the image capturing module. Therefore, it has become a target of all image capturing module manufacturers to further reduce the size of the capturing module that has more functions.
There are various types of auto-focus driving structures for the conventional miniature lens. Among others, the voice coil motor (VCM) is the currently most widely employed auto-focus driving structure. The VCM includes an assembly of coils, magnets and plate springs to hold a lens thereto, so that the lens is able to move forward and rearward in an optical axis direction to thereby achieve the object of auto focusing or zooming. The VCM has the advantages of small size, low power consumption, accurately actuated displacement, and cost-effective, and is therefore very suitable for short-distance driving in miniature lens auto-focusing.
With respect to the anti-shake function, it is achieved mainly through several ways. For example, the imaging element can utilize a compensation movement of a mechanism supporting frame to offset the influence of shake during shooting picture on the forming of a blurred image. Or, the lens can be provided with a mechanical structure to eliminate the shake. Or, two gyro sensors can be used to detect any angular vibration of the imaging element in yaw and pitch directions, and actuate the lens by magnetic force to compensate such vibration.
The same inventor of the present invention filed U.S. patent application Ser. No. 12/630,688 entitled “Anti-shake Auto-focus Module Structure” on Dec. 3, 2009. According to the disclosure of U.S. patent application Ser. No. 12/630,688, a movement signal generated by a shake sensor is used to drive the whole auto-focus module to instantaneously move along x-axis or y-axis direction, so as to compensate any shake caused by hands.
Now, based on the previous structural design, the inventor further designs a new anti-shake structure for the auto-focus module. Unlike the U.S. patent application Ser. No. 12/630,688 that teaches the instantaneous movement of the whole auto-focus module to compensate any shake, the new anti-shake structure in the present invention moves only one compensation lens in the camera lens to achieve the compensation of shake caused by hands, so that the anti-shake structure is simpler, the shake compensation can be driven with lower power consumption, and the effect of shake compensation can be produced more quickly to satisfy the requirement for use with an advanced camera lens module.